vGEM buffers are useful for passing data between software clients and
hardware renders. By allowing the user to create and attach fences to
the exported vGEM buffers (on the dma-buf), the user can implement a
deferred renderer and queue hardware operations like flipping and then
signal the buffer readiness (i.e. this allows the user to schedule
operations out-of-order, but have them complete in-order).
This also makes it much easier to write tightly controlled testcases for
dma-buf fencing and signaling between hardware drivers.
v2: Don't pretend the fences exist in an ordered timeline, but allocate
a separate fence-context for each fence so that the fences are
unordered.
v3: Make the debug output more interesting, and show the signaled status.
v4: Automatically signal the fence to prevent userspace from
indefinitely hanging drivers.
Testcase: igt/vgem_basic/dmabuf-fence
Testcase: igt/vgem_slow/nohang
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Zach Reizner <zachr@google.com>
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Zach Reizner <zachr@google.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468571471-12610-1-git-send-email-chris@chris-wilson.co.uk
Enable the standard GEM dma-buf interface provided by the DRM core, but
only for exporting the VGEM object. This allows passing around the VGEM
objects created from the dumb interface and using them as sources
elsewhere. Creating a VGEM object for a foriegn handle is not supported.
v2: With additional completeness.
v3: Need to clear the CPU cache upon exporting the dma-addresses.
v4: Use drm_gem_put_pages() as well.
v5: Use drm_prime_pages_to_sg()
Testcase: igt/vgem_basic/dmabuf-*
Testcase: igt/prime_vgem
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Zach Reizner <zachr@google.com>
Acked-by: Zach Reizner <zachr@google.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468242488-1505-3-git-send-email-chris@chris-wilson.co.uk
It's duplicating (without using some of the helpers) drm_gem_mmap with
the addition that it can redirect to drm-buf mmap support. But prime
import/export was dropped in
commit 990ed27207
Author: Rob Clark <robdclark@gmail.com>
Date: Thu May 21 11:58:30 2015 -0400
drm/vgem: drop DRIVER_PRIME (v2)
for now, so this is dead code. And since I want to rework the locking
for drm_gem_mmap it seems simpler to de-dupe this code for now and
then start over with the reworked one again, if we want to resurrect
this all indeed.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://mid.gmane.org/1444894601-5200-8-git-send-email-daniel.vetter@ffwll.ch
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
For actual sharing of buffers with other drivers (ie. actual hardware)
we'll need to pimp things out a bit better to deal w/ caching, multiple
memory domains, etc. See thread:
http://lists.freedesktop.org/archives/dri-devel/2015-May/083160.html
But for the llvmpipe use-case this isn't a problem. Nor do we really
need prime/dri3 (dri2 is sufficient). So until the other issues are
sorted lets remove DRIVER_PRIME.
v2: also drop the dead code
[airlied:
Okay I'm convinced this API could have a lot of use cases
that are really really bad, yes the upload use case is valid
however that isn't the only use case enabled, and if we allow
all the other use cases, people will start to (ab)use them,
and then they'll be ABI and my life will get worse, so disable
PRIME for now]
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch implements the virtual GEM driver with PRIME sharing which
allows vgem to import a gem object from other drivers for the purpose
of mmap-ing them to userspace. The mmap is done using the mmap
operation exported by other drivers.
v2: remove platform_device and do not attach to dma bufs
v3: use drm helpers for get/put pages
v4: correct dumb create pitch
Reviewed-by: Rob Clark <robdclark@gmail.com> (v3)
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org> (v3)
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Zach Reizner <zachr@google.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
